We have no FTP access to free hosted WordPress.com blogs.
We cannot create child themes. We cannot edit templates or themes. We cannot use stylesheets from other themes. We cannot upload any third party themes either. I suggest you read this for clarity: http://en.support.wordpress.com/com-vs-org/

We provide support only for free hosted WordPress.COM blogs and it sounds like you are posting to the wrong support forum. WordPress.com and WordPress.org are completely separate, have different log-ins and run different versions of themes with same names.

If you don't have a username account at WordPress.ORG click http://wordpress.org/support/ and register one on the top right hand corner of the page that opens, so you can post to the support forums there and receive advice from WordPress.ORG bloggers.